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61.
In vivo expression of a nonselected gene transferred into murine hematopoietic stem cells by electroporation 总被引:4,自引:0,他引:4
R Narayanan M M Jastreboff C F Chiu J R Bertino 《Biochemical and biophysical research communications》1986,141(3):1018-1024
Mouse bone marrow cells were subjected to electroporation in the presence of RSVCAT and SV2NEO plasmids. CAT activity was detected in the G-418 resistant granulocyte-macrophage colonies. RSVCAT electroporated into primary bone marrow cells, repopulated lethally irradiated mice as demonstrated by the persistence of CAT activity in the hematopoietic tissues showing that electroporation can offer a powerful mode of gene transfer into bone marrow cells. 相似文献
62.
We address the hypothesis that postures adopted during grammatical pauses in speech production are more “mechanically advantageous” than absolute rest positions for facilitating efficient postural motor control of vocal tract articulators. We quantify vocal tract posture corresponding to inter-speech pauses, absolute rest intervals as well as vowel and consonant intervals using automated analysis of video captured with real-time magnetic resonance imaging during production of read and spontaneous speech by 5 healthy speakers of American English. We then use locally-weighted linear regression to estimate the articulatory forward map from low-level articulator variables to high-level task/goal variables for these postures. We quantify the overall magnitude of the first derivative of the forward map as a measure of mechanical advantage. We find that postures assumed during grammatical pauses in speech as well as speech-ready postures are significantly more mechanically advantageous than postures assumed during absolute rest. Further, these postures represent empirical extremes of mechanical advantage, between which lie the postures assumed during various vowels and consonants. Relative mechanical advantage of different postures might be an important physical constraint influencing planning and control of speech production. 相似文献
63.
64.
Aruliah Rajasekar Thambidurai Ganesh Babu Sundaram Maruthamuthu Shunmugiah Thevar Karutha Pandian Sidhan Mohanan Narayanan Palaniswamy 《World journal of microbiology & biotechnology》2007,23(8):1065-1074
A facultative anaerobic species Serratia marcescens ACE2 isolated from the corrosion products of a diesel-transporting pipeline in North West India was identified by 16S rDNA
sequence analysis. The role of Serratia marcesens ACE2 on biodegradation of commercial corrosion inhibitor (CCI) and its influence on the corrosion of API 5LX steel has been
enlightened. The degrading strain ACE2 is involved in the process of corrosion of steel API 5LX and also utilizes the inhibitor
as organic source. The quantitative biodegradation efficiency of corrosion inhibitor was 58%, which was calculated by gas
chromatography mass spectrum analysis. The effect of CCI on the growth of bacteria and its corrosion inhibition efficiency
were investigated. Additionally, the role of this bacterium in corrosion of steel has been investigated by powder X-ray diffractometer
(XRD) and scanning electron microscope studies. The presence of high-intensity ferric oxides and manganese oxides noticed
from the XRD indicates that ACE2 enhances the corrosion process in presence of inhibitor as a carbon source. This basic study
will be useful for the development of new approaches for the detection, monitoring and control of microbial corrosion in petroleum
product pipelines. 相似文献
65.
Davis FP Barkan DT Eswar N McKerrow JH Sali A 《Protein science : a publication of the Protein Society》2007,16(12):2585-2596
Pathogens have evolved numerous strategies to infect their hosts, while hosts have evolved immune responses and other defenses to these foreign challenges. The vast majority of host-pathogen interactions involve protein-protein recognition, yet our current understanding of these interactions is limited. Here, we present and apply a computational whole-genome protocol that generates testable predictions of host-pathogen protein interactions. The protocol first scans the host and pathogen genomes for proteins with similarity to known protein complexes, then assesses these putative interactions, using structure if available, and, finally, filters the remaining interactions using biological context, such as the stage-specific expression of pathogen proteins and tissue expression of host proteins. The technique was applied to 10 pathogens, including species of Mycobacterium, apicomplexa, and kinetoplastida, responsible for "neglected" human diseases. The method was assessed by (1) comparison to a set of known host-pathogen interactions, (2) comparison to gene expression and essentiality data describing host and pathogen genes involved in infection, and (3) analysis of the functional properties of the human proteins predicted to interact with pathogen proteins, demonstrating an enrichment for functionally relevant host-pathogen interactions. We present several specific predictions that warrant experimental follow-up, including interactions from previously characterized mechanisms, such as cytoadhesion and protease inhibition, as well as suspected interactions in hypothesized networks, such as apoptotic pathways. Our computational method provides a means to mine whole-genome data and is complementary to experimental efforts in elucidating networks of host-pathogen protein interactions. 相似文献
66.
67.
Sujatha Narayanan Kutty Marco Valerio Bernasconi Frantiek ifner Rudolf Meier 《Cladistics : the international journal of the Willi Hennig Society》2007,23(1):64-83
The 60 000 described species of Cyclorrhapha are characterized by an unusual diversity in larval life‐history traits, which range from saprophagy over phytophagy to parasitism and predation. However, the direction of evolutionary change between the different modes remains unclear. Here, we use the Scathophagidae (Diptera) for reconstructing the direction of change in this relatively small family (≈ 250 spp.) whose larval habits mirror the diversity in natural history found in Cyclorrhapha. We subjected a molecular data set for 63 species (22 genera) and DNA sequences from seven genes (12S, 16S, Cytb, COI, 28S, Ef1‐alfa, Pol II) to an extensive sensitivity analysis and compare the performance of three different alignment strategies (manual, Clustal, POY). We find that the default Clustal alignment performs worst as judged by character incongruence, topological congruence and branch support. For this alignment, scoring indels as a fifth character state worsens character incongruence and topological congruence. However, manual alignment and direct optimization perform similarly well and yield near‐identical trees, although branch support is lower for the direct‐optimization trees. All three alignment techniques favor the upweighting of transversion. We furthermore confirm the independence of the concepts “node support” and “node stability” by documenting several cases of poorly supported nodes being very stable and cases of well supported nodes being unstable. We confirm the monophyly of the Scathophagidae, its two constituent subfamilies, and most genera. We demonstrate that phytophagy in the form of leaf mining is the ancestral larval feeding habit for Scathophagidae. From phytophagy, two shifts to saprophagy and one shift to predation has occurred while a second origin of predation is from a saprophagous ancestor. © The Willi Hennig Society 2006. 相似文献
68.
Nireeksha Sudhir Rama Varma Marah Damdoum Mohammed Amjed Alsaegh Mithra N. Hegde Suchetha N. Kumari Srinivasan Ramamurthy Jayaraj Narayanan Eisha Imran Juzer Shabbir Zohaib Khurshid 《Current issues in molecular biology》2021,43(1):116
The role of inflammatory mediators in dental pulp is unique. The local environment of pulp responds to any changes in the physiology that are highly fundamental, like odontoblast cell differentiation and other secretory activity. The aim of this review is to assess the role of cathelicidins based on their capacity to heal wounds, their immunomodulatory potential, and their ability to stimulate cytokine production and stimulate immune-inflammatory response in pulp and periapex. Accessible electronic databases were searched to find studies reporting the role of cathelicidins in pulpal inflammation and regeneration published between September 2010 and September 2020. The search was performed using the following databases: Medline, Scopus, Web of Science, SciELO and PubMed. The electronic search was performed using the combination of keywords “cathelicidins” and “dental pulp inflammation”. On the basis of previous studies, it can be inferred that LL-37 plays an important role in odontoblastic cell differentiation and stimulation of antimicrobial peptides. Furthermore, based on these outcomes, it can be concluded that LL-37 plays an important role in reparative dentin formation and provides signaling for defense by activating the innate immune system. 相似文献
69.
Effect of Triphala on oxidative stress and on cell-mediated immune response against noise stress in rats 总被引:2,自引:0,他引:2
Srikumar R Parthasarathy NJ Manikandan S Narayanan GS Sheeladevi R 《Molecular and cellular biochemistry》2006,283(1-2):67-74
Stress is one of the basic factors in the etiology of number of diseases. The present study was aimed to investigate the effect
of Triphala (Terminalia chebula, Terminalia belerica and Emblica officinalis) on noise-stress induced alterations in the antioxidant status and on the cell-mediated immune response in Wistar strain
male albino rats. Noise-stress employed in this study was 100 dB for 4 h/d/15 days and Triphala was used at a dose of 1 g/kg/b.w/48
days. Eight different groups of rats namely, non-immunized: control, Triphala, noise-stress, Triphala with noise-stress, and
corresponding immunized groups were used. Sheep red blood cells (5×109 cells/ml) were used to immunize the animals. Biochemical indicators of oxidative stress namely lipid peroxidation, antioxidants
superoxide dismutase (SOD), catalase (CAT), glutathione peroxidase (GPx), ascorbic acid in plasma and tissues (thymus and
spleen) and SOD, GPx and corticosterone level in plasma were estimated. Cell-mediated immune response namely foot pad thickness
(FPT) and leukocyte migration inhibition (LMI) test were performed only in immunized groups. Results showed that noise-stress
significantly increased the lipid peroxidation and corticosterone level with concomitant depletion of antioxidants in plasma
and tissues of both non-immunized and immunized rats. Noise-stress significantly suppressed the cell-mediated immune response
by decreased FPT with an enhanced LMI test. The supplementation with Triphala prevents the noise-stress induced changes in
the antioxidant as well as cell-mediated immune response in rats. This study concludes that Triphala restores the noise-stress
induced changes may be due to its antioxidant properties. 相似文献
70.
Shazia Khan Sathya Narayanan Nagarajan Amit Parikh Sharmishtha Samantaray Albel Singh Devanand Kumar Rajendra P. Roy Apoorva Bhatt Vinay Kumar Nandicoori 《The Journal of biological chemistry》2010,285(48):37860-37871
InhA, the primary target for the first line anti-tuberculosis drug isoniazid, is a key enzyme of the fatty-acid synthase II system involved in mycolic acid biosynthesis in Mycobacterium tuberculosis. In this study, we show that InhA is a substrate for mycobacterial serine/threonine protein kinases. Using a novel approach to validate phosphorylation of a substrate by multiple kinases in a surrogate host (Escherichia coli), we have demonstrated efficient phosphorylation of InhA by PknA, PknB, and PknH, and to a lower extent by PknF. Additionally, the sites targeted by PknA/PknB have been identified and shown to be predominantly located at the C terminus of InhA. Results demonstrate in vivo phosphorylation of InhA in mycobacteria and validate Thr-266 as one of the key sites of phosphorylation. Significantly, our studies reveal that the phosphorylation of InhA by kinases modulates its biochemical activity, with phosphorylation resulting in decreased enzymatic activity. Co-expression of kinase and InhA alters the growth dynamics of Mycobacterium smegmatis, suggesting that InhA phosphorylation in vivo is an important event in regulating its activity. An InhA-T266E mutant, which mimics constitutive phosphorylation, is unable to rescue an M. smegmatis conditional inhA gene replacement mutant, emphasizing the critical role of Thr-266 in mediating post-translational regulation of InhA activity. The involvement of various serine/threonine kinases in modulating the activity of a number of enzymes of the mycolic acid synthesis pathway, including InhA, accentuates the intricacies of mycobacterial signaling networks in parallel with the changing environment. 相似文献